A telephone emergency alarm response system is the subject of U.S. Pat. Nos. 3,989,900 and 4,064,368 of the same assignee as herein and comprises an alarm system coupled to a residential telephone and capable of sending an alarm to a central station in response to actuation of a switch or call button. The switch can be wired to the alarm system or can be part of a wireless radio transmitter unit as described in U.S. Pat. No. 4,064,368. Such emergency alarm systems provide monitoring of and response to the needs of elderly or infirm persons confined to their residences, and the comfort and security of those persons can be enhanced by the ready accessibility of the switch for use in the event that an emergency occurs.
Portable transmitter units of known construction are not watertight and therefore cannot be worn or carried by a user in the bathtub or shower, which is a frequent site of accidental falls and where the accessibility of the unit is important in summoning help. Presently known units are also of a size and weight to discourage their being carried about by a user, with resultant increased risk to the user in the event of an emergency. In addition, present units have relatively short battery life requiring a battery change at least once each year.